Energy Co-op of Vermont has reported it is expanding a solar water heating program to cover Addison County.

In fact, the program’s popularity is making it hard to keep up with demand, the co-op says.

The program currently serves Chittenden County as well as parts of Washington, Grand Isle, Franklin and Lamoille counties.

The co-op solar hot water program is designed to help Vermonters save money and energy through heating their water with solar power. The program is available to any home or business owner in Vermont. In 2012, the first year of the program, Co-op Solar assisted in installing more than 40 hot water systems.

Last year, the program was available only in Chittenden County, but it expanded into other counties in 2013.

U.S. Sen. Bernard Sanders said in a statement: “What is particularly exciting about this program is that people can move in this direction without spending any more money on their fuel bills than they currently are, because they’re going to pay off their loan from the credit union by reduced fuel costs.”

Support from high-profile officials such as Sanders was instrumental in getting this year’s program off the ground February, according to the co-op.

Other supporters included Andrew Perchlik of the Department of Public Service and the Clean Energy Development Fund, U.S. Sen. Patrick Leahy and U.S. Rep. Peter Welch.

Locally, interest in the solar hot water program is high, the co-op said. Washington County was home to eight of the 44 systems installed in 2013, or 18 percent.

Other counties around the state also bought into the program because of the systems’ low prices, the co-op said. Joining with Sunward Systems, a local manufacturer of solar heating equipment, Co-op Solar was able to provide Vermonters with low-priced, locally made solar systems.

“This collaboration between Sunward Systems and the Energy Co-op of Vermont is exactly the kind of story Peter Welch is planning to bring down to Congress,” said Welch’s deputy state director Jon Copans. “The product is being assembled here in Vermont by Vermonters. We’re saving people money on their energy bill and reducing fossil fuel use and our greenhouse gas emissions.”

Solar hot water customers save additional money due to a 30 percent federal tax credit, as well as $900 to $1,200 state incentive. Combined, the federal tax credit and state incentive reduce the price of solar hot water systems by 50 percent and, according to the co-op, a typical four-person household can save $700 to $1,000 by installing solar hot water.

“These new solar hot water systems will pay for themselves through energy savings,” said John Quinney, general manager at the co-op. “It may be the best investment you can make for your home and planet.”

Benjamin Griffin of Energy Co-op of Vermont explained the environmental benefit of installing each solar hot water system as the equivalent of taking one car off the road in terms of carbon dioxide emissions.

Despite all the support, there is some concern that the solar hot water program will not continue in 2014. In the past Energy Co-op of Vermont has received a portion of its funding from the Clean Energy Development Fund. The fund had previously received money from Entergy Vermont Yankee, but due to Vermont Yankee’s state licensing issues, that money may not be available in the future.